A new method for preserving whole organs at temperatures of -22 degrees C or below has been found successful with the canine kidney. This technique utilizing freeze rates of 1-2 degrees C/minuts, and various cryoprotective agents such as methylprednisolone, isoproterenol, fluoride, dimethylsulfoxide and glycerol is now being used on the whole canine pancreas, without duodenum. Thaw rates of greater than 70 degrees C/minute are obtained in a specially designed microwave oven. Similar techniques are also being used to preserve previously isolated islet cells of the pancreas. With either the previously frozen whole organ or islet cells, the ultimate test of mobility is the survival of the pancreatectomized dog. Both auto- and allograft experiments are being done.